The goals of this program are to use biological characteristics of tumor cells as a means for improving grading of human cancer through use of more objective parameters. The object of grading tumors is to estimate the potential of the tumor for growth, invasion, and metastasis which are important factors to clinicians in planning therapy. Tumor cell attachment to new substrates is being compared to normal cell attachment using reflection contrast microscopy. A major characteristic of cancer cells, release from density dependent growth control, is also being studied as is the role of lamellar cytoplasm in tumor cell growth. A long-term study of the pathology and dynamics of infections in immune compromised patients is in progress. A preliminary investigation of the histiogenesis of lepromatous and histoid leprosy as a model of mesenchymal dysplasia has been started. One project characterizes human cancer cell clonogenic populations in archival tissues and with needle aspiration cytology. A study of endometrial epithelium and its growth dynamics in relation to endometrial hyperplasia is now underway, and a separate project on the dynamics of cellular response to cytostatic agents in head and neck cancer is in progress.